مشخصات پژوهش

Industrial and agricultural activities are the main causes of heavy metals pollution. Existence of heavy metals in aquatic environment has been known to cause various health problems. The removal of hazardous heavy metals from aqueous media including drinking water, wastewater, and soil solutions is of environmental importance. Various nanomaterials are extensively used in the heavy metals removal from solutions. Among them, clay minerals have gathered particular interest owing to their unique features such as, high specific surface area, low toxicity and natural availability at low price. Halloysite nanotubes (Hal), similar to the platy kaolin, are clay minerals with a predominantly hollow tubular structure. They consist in 10–15 aluminosilicate layers with an external surface constituted by siloxane groups and an inner lumen composed of aluminol groups. Owing to this peculiar composition, Hal are positively charged in the interior whereas a negative charge is present on the external surface in a wide pH range. Therefore, many researches about the adsorption properties of halloysite have been reported. The removal of Cr (VI) by HDTMA modified Hal, Pb (II) by amino derivatives of Hal, U (VI) by isothiouronium salts functionalized Hal, Cr(VI), Cd(II), Cu(II) and Pb(II) by immobilized Hal and Fe3O4 NPs on PEO/CS composite fibers and other successful studies, revealed the excellent performance of halloysite for adsorption of heavy metals from wastewaters.